Konagasō Pottery Kiln Ruins: A Muromachi-Period Seto Ware Kiln Site
Site at a Glance
- Rating
- 3.9
- Popularity
- Very Low
- Country
- Japan
- Primary era
- Medieval
- External website
- Open
- Eras represented
- Medieval, Early Modern
- Civilizations
- Ashikaga shogunate, Tokugawa
- Site type
- Economic
- Remains
- Production Complex
On this page13 sections
History
Konagasō Pottery Kiln ruins are a Japanese Seto ware kiln site in Seto, Aichi, built during the Muromachi period in the late fourteenth or early fifteenth century. Cut into a hillside on the northern foothills of Mount Sanage, the kiln belongs to the Ko-Seto, or “Old Seto,” phase of medieval ceramic production. Its remains illuminate the technology, equipment, and organization of labor used in the early Seto pottery industry.
Medieval Seto production
The kiln operated during the late fourteenth to early fifteenth century, when Seto ware was developing as one of Japan’s major historical pottery traditions. The site formed part of the wider Seto industry, in which approximately 100 of the roughly 800 identified kiln ruins are associated with the Ko-Seto phase. Pottery fragments from the medieval period include jars, vases, tea bowls, and other vessels, most of them undecorated.
Local tradition connects the kiln with Kato Kagemasa, an early founding figure of Seto pottery. This association is a foundation tradition rather than an established historical fact. The medieval kiln was eventually abandoned, but its remains continued to be known by the Edo period.
Edo-period reuse
The kiln was repaired and altered around 1699, during the Genroku era, for a short period of renewed use. An eighteenth-century record describes this reuse, while excavations identified a smaller group of Genroku-period artifacts alongside the much larger medieval assemblage. Edo-period tea utensils and related kiln tools came from the area immediately in front of the kiln opening, showing that the earlier installation was adapted for later production.
Investigation and preservation
Academic investigation began in 1946, when the Japan Ceramic Association excavated the site as its first kiln-ruin investigation. That work recovered an Edo-period kiln tool known as an ebuta. Resin was applied to preserve the kiln body in 1969, and a protective shelter was built over the remains. The site became a National Historic Site of Japan on July 13, 1971. The protected area was enlarged through additional designations in 2002 and 2015.
Between 1996 and 2000, the Seto Buried Cultural Properties Center carried out test excavations around the kiln body, forecourt, and workshop remains to define the site’s extent. The ash field was examined in 2003, and later Heisei-period investigations included replacement of the deteriorated shelter. Excavations have recovered approximately 170,000 Muromachi-period artifacts and about 350 objects from the Genroku phase. Some of this material is displayed at the Seto-Gura Museum in Seto.
Remains
The kiln structure
Combustion chamber
Konagasō is a semi-underground anagama, a sloping kiln in which the firebox, firing chamber, and flue form one connected passage. The surviving kiln body measures approximately 8.64 meters in length and reaches a maximum width of about 2.82 meters. Its combustion chamber slopes by roughly 12 degrees. Stones measuring about 30 to 60 centimeters were set into the chamber floor and side walls, and firing supports were embedded in the flame-dividing pillar to strengthen the structure.
Firing chamber
The firing chamber is divided into front and rear sections by a ceiling-hanging barrier and five flame-dividing pillars. These pillars were made by reusing kiln furniture, the supports and equipment that held vessels during firing. A flame-dividing pillar separates and distributes heat within a kiln. The arrangement at Konagasō is regarded as unique and as an important precursor to later noborigama climbing kilns, whose successive firing chambers rise along a slope.
The front section of the firing chamber is 2.5 meters long. Its ceiling has been lost, but rows of firing supports remain, along with reinforcement traces along the side walls. The rear section measures 3.3 meters and retains a ceiling reaching up to 1.6 meters. Its role during the Genroku reuse remains uncertain. The floor slopes by approximately 32 degrees in the rear of the firing chamber.
Flue
The flue slopes at about 30 degrees. Its floor has collapsed, while erosion has removed its sides and terminal section. The surviving flue is therefore regarded as part of the kiln’s original Muromachi-period construction. A group of Muromachi-period firing supports had been discarded to the north of it.
Forecourt and ash field
Forecourt pit
Immediately in front of the kiln, excavation revealed a large forecourt pit measuring 4 by 5 meters and 1.5 meters deep, together with numerous smaller pits. The area was covered with earth for preservation and now lies beneath the shelter’s stairway. The pit and its immediate surroundings yielded the Genroku-period pottery and kiln tools, including tea utensils associated with the kiln’s brief Edo-period reuse.
Ash field
The ash field extends for approximately 30 by 30 meters from the forest road in front of the kiln toward a stream. It contains numerous pottery fragments and kiln tools, and sherds can still occasionally be found around the stream. The area preserves the discarded material of the pottery-making process and helps define the wider working environment around the kiln.
Workshop area and archaeological finds
On the kiln’s eastern slope, excavations identified a Muromachi-period workshop at the middle level. It included a drainage outlet and two holes for potters’ wheels. A drying-area installation occupied the upper level. Together with the forecourt and ash field, these features show that production extended beyond the kiln body into organized work areas on the surrounding slope.
The excavated assemblage includes numerous Seto ware fragments from jars, vases, tea bowls, and other vessels. Most of the recovered material belongs to the medieval phase, while the Genroku objects came from the restricted area immediately before the kiln opening. The site covers approximately 1,509 square meters and preserves physical evidence for changing kiln use from the Muromachi period to the Edo period.
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